小脑参与痛觉调节的fMRI研究

Cerebellar pain modulation: functional MRI study

目的 利用功能磁共振成像技术（fMRI）观察小脑各亚区在不同强度电刺激时的激活反应，探讨小脑对于痛觉调控的作用。方法 对10名右利手健康志愿者分别施加1倍痛阈、3倍痛阈两个不同强度的电刺激任务，同期进行全脑fMRI扫描，应用功能性神经图像分析（AFAI）软件包进行包处理以显示小脑激活的变化。结果 非伤害性电刺激（1倍痛阈强度）主要激活对侧小脑半球小叶Ⅵ、Ⅶ区和同侧小脑半球Ⅶ、Ⅷ区，以同侧半球的BOLD信号较强；伤害性电刺激（3倍痛阈强度）诱发的激活区主要位于同侧小脑半球小叶Ⅲ-Ⅵ区，对侧小脑半球Ⅵ区，前蚓旁区和深部小脑核团的一部分（顶核和齿状核），其中仍以同侧激活区范围较大，信号亦明显强于对侧。结论 高强度痛觉电刺激额外激活同侧小脑半球小叶Ⅲ-Ⅵ，前蚓部，蚓旁区和深部小脑核团，这些脑区应该属于小脑作害感受性环路的一部分，它们可能在全身痛觉调控网络中更为重要。

Objective To observe activated changes of cerebellar subregions induced by electrical stimulation of different intensity in function magnetic resonance imaging （fMRI） and discuss the effect of these areas in pain modulation. Methods Ten healthy right-handed volunteers were performed respectively with different electrical stimulation of 1, 3 times pain threshold intensity. The whole-brain fMRI scanning was implemented at the same time. All data were postprocessed by means of analysis of functional neuroimages （AFNI） to reveal the regional activated changes of cerebellum. Results The activation elicited by non-noxious electrical stimulation mainly located in the contralateral cerebellar hemispheric lobule Ⅵ, and ipsilateral lobule Ⅶ,Ⅷ, the BOLD signal of ipsilateral hemisphere showed relatively significant; When applying noxious electrical stimulation, the ipsilateral cerebellar hemispheric lobule Ⅲ -Ⅵ, contralateral lobule Ⅵ, anterior vermis, paravermis area and part of the deep cerebellar nuclei （dentate nucleus and fastigial nucleus） were activated simultaneously, the activation response of ipsilateral cerebellar hemisphere still displayed more strongly with larger activated region than contralateral hemisphere. Conclusion In contrast to non-noxious electrical stimulation, noxious stimulation additionally revealed activation in the ipsilateral cerebellar hemispheric lobule Ⅲ-Ⅵ, anterior vermis, paravermis area and part of the deep cerebellar nuclei, these areas ought to belong to the part of cerebellar nociceptive circuits and may be more important in body pain modulation network.